ocfs2: use the new DLM operation callbacks while requesting new lockspace
authorGoldwyn Rodrigues <rgoldwyn@suse.de>
Tue, 21 Jan 2014 23:48:32 +0000 (15:48 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 22 Jan 2014 00:19:42 +0000 (16:19 -0800)
commitc994c2ebdbbc391a42f177c8eb7882ebf3f142d8
tree0f0240ae61f86140b0660ce224b1eff26d89ce3c
parent415036303319c0a46caf9059711710bfa34e3bf3
ocfs2: use the new DLM operation callbacks while requesting new lockspace

Attempt to use the new DLM operations.  If it is not supported, use the
traditional ocfs2_controld.

To exchange ocfs2 versioning, we use the LVB of the version dlm lock.
It first attempts to take the lock in EX mode (non-blocking).  If
successful (which means it is the first mount), it writes the version
number and downconverts to PR lock.  If it is unsuccessful, it reads the
version from the lock.

If this becomes the standard (with o2cb as well), it could simplify
userspace tools to check if the filesystem is mounted on other nodes.

Dan: Since ocfs2_protocol_version are two u8 values, the additional
checks with LONG* don't make sense.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ocfs2/stack_user.c